#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std; 

#define N 1000001

int ar[N]; 
int n; 

int main()
{
	int sum=0;
	cin>>n;
	for (int i=1; i<=n; i++) {
		for (int j=i; j<=n; j+=i) {
			ar[j]++; 
		}
	}
	for (int i=1; i<=n; i++) {
		//printf("i=%d, ai=%d\n", i, ar[i]); 
		sum += ar[i]; 
	}
	cout<<sum<<endl; 
	return 0; 
}


